scholarly journals Low-Complexity Distortionless Techniques for Peak Power Reduction in OFDM Communication Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-13
Author(s):  
A. Ghassemi ◽  
T. A. Gulliver
Keyword(s):  
Computational Complexity ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Low Complexity ◽  
Inverse Discrete Fourier Transform ◽  
Peak Power Reduction ◽  
And Performance ◽  
Selective Mapping ◽  
Papr Performance

A high peak-to-average power ratio (PAPR) is one of the major drawbacks to using orthogonal frequency division multiplexing (OFDM) modulation. The three most effective distortionless techniques for PAPR reduction are partial transmit sequence (PTS), selective mapping (SLM), and tone reservation (TR). However, the high computational complexity due to the inverse discrete Fourier transform (IDFT) is a problem with these approaches. Implementation of these techniques typically employ direct computation of the IDFT, which is not the most efficient solution. In this paper, we consider the development and performance analysis of these distortionless techniques in conjunction with low-complexity IFFT algorithms to reduce the PAPR of the OFDM signal. Recently, proposed IFFT-based techniques are shown to substantially reduce the computational complexity and improve PAPR performance.

Combined Envelope Scaling with Modified SLM Method for PAPR Reduction in OFDM-Based VLC Systems

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ridha Touhami ◽  
Djamal Slimani ◽  
Ayad Atiyah Abdulkafi ◽  
Yaseein Soubhi Hussein ◽  
Mohamad Yusoff Alias
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Visible Light Communication ◽  
Low Complexity ◽  
Optical Communication Systems ◽  
High Spectral Efficiency ◽  
Low Complexity Implementation ◽  
Scaling Process ◽  
Selective Mapping

AbstractOrthogonal frequency-division multiplexing technique (OFDM) has been adopted widely as a modulation technique for radio frequency (RF) and optical communication systems such as visible-light communication (VLC) due to its high spectral efficiency and low-complexity implementation. VLC-OFDM is recommended in 5 G mobile communication. However, VLC-OFDM suffer from the high peak to-average power ratio (PAPR). In this paper, a modified selective mapping (MSLM) method is applied to the proposed system followed by a new envelope scaling process for further reductions in PAPR of VLC-OFDM system. Simulation results show that the proposed method reduces the PAPR by about 6.8 and 1.7 dB comparing with the original signal and the traditional SLM with a number of rotation vector U = 8, respectively.

scholarly journals PAPR Performance Analysis of low Complexity SLM for Various Phase Sequences in MIMO-OFDM System

2019 ◽  
Vol 8 (2) ◽  
pp. 4347-4353
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Multipath Fading ◽  
Low Complexity ◽  
Superior Performance ◽  
Ofdm Systems ◽  
Phase Sequence ◽  
Mimo Ofdm ◽  
Papr Performance

Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO OFDM) is a key technology for contemporary communication systems due to its spectral efficiency, higher data rates, better diversity gain, good link reliability and both inter symbol interference (ISI) and multipath fading free transmission. However, due to the presence of OFDM, MIMO-OFDM suffers from high peak to average power ratio (PAPR). Even though, several schemes are available to mitigate PAPR, there is no standard solution. Selective Mapping (SLM) significantly reduces the PAPR in OFDM systems at the cost of computational complexity (CC). The CC of SLM can be reduced by proper design of SLM. This paper considers a low complexity SLM (LC SLM) scheme in which both the CC and length of the index of selected phase sequence are significantly reduced. The PAPR of an SLM-OFDM depends on the number of subcarriers in OFDM, the number of candidate blocks in SLM and selected phase sequence and this paper investigate various phase sequences and analyses their PAPR performance. Simulation results show the superior performance of Riemann sequence over the other phase sequences.

scholarly journals An Efficient Adaptive Technique with Low Complexity for Reducing PAPR in OFDM-Based Cognitive Radio

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hefdhallah Sakran ◽  
Omar Nasr ◽  
Mona Shokair
Keyword(s):  
Cognitive Radio ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Low Complexity ◽  
Papr Reduction ◽  
Modulation Scheme ◽  
Ofdm Systems ◽  
Cpu Time ◽  
Reduction Techniques ◽  
Selective Mapping

Cognitive radio (CR) is considered nowadays as a strong candidate solution for the spectrum scarcity problem. On standards level, many cognitive radio standards have chosen Non-Contiguous Orthogonal Frequency Division Multiplexing (NC-OFDM) as their modulation scheme. Similar to OFDM, NC-OFDM suffers from the problem of having a high Peak to Average Power Ratio (PAPR). If not solved, either the transmitted signal will be distorted, which will cause interference to primary (licensed) users, or the effeciency of the power amplifier will be seriously degraded. The effect of the PAPR problem in NC-OFDM based cognitive radio networks is worse than normal OFDM systems. In this paper, we propose enhanced techniques to reduce the PAPR in NC-OFDM systems. We start by showing that combining two standard PAPR reduction techniques (interleaver-based and selective mapping) results in a lower PAPR than using them individually. Then, an “adaptive number of interleavers” will be proposed that achieves the same performance of conventional interleaver-based PAPR reduction while reducing the CPU time by 41.3%. Finally, adaptive joint interleaver with selective mapping is presented, and we show that it gives the same performance as conventional interleaver-based technique, with reduction in CPU time by a factor of 50.1%.

scholarly journals A Multi-Carrier Waveform Design for 5G and beyond Communication Systems

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1466
Author(s):  
Imran Baig ◽  
Umer Farooq ◽  
Najam Ul Hasan ◽  
Manaf Zghaibeh ◽  
Varun Jeoti
Keyword(s):  
Communication Networks ◽  
Spectral Efficiency ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Research Problem ◽  
Cumulative Distribution ◽  
Fourth Generation ◽  
Power Domain ◽  
Selective Mapping

The next generation communication network (NGCN) is expected to provide higher spectral efficiency, low latency, large throughput and massive machine-to-machine type communications. In this regard, the design of the multi-carrier waveform (MCW) is posing a major research problem for the NGCN. To overcome the stated problem, a lot of state-of-the-art work exists that proposes various MCW alternative to the standard orthogonal frequency division multiplexing (OFDM) waveform. It is true that OFDM was used in a number of real-time communication systems of fourth generation (4G) networks. However, their use in the upcoming fifth generation (5G) network is not very feasible. This is because of the strict requirements of 5G communication systems, which also extend beyond 5G systems; hence rendering the use of OFDM infeasible for newer communication standards. To satisfy the requirements of upcoming communication networks, there is a dire need for MCWs with better flexibility. In this regard, a precoding-based MCW has been proposed. The proposed MCW fulfills the requirements of the NGCN in terms of low peak-to-average power ratio (PAPR), high spectral efficiency and throughput. The MCW proposed in this work uses power-domain multiplexing such as non-orthogonal multiple access (NOMA) and phase rotation by using the selective mapping (SLM) and generalized chirp-like (GCL) precoding of the input signal to the universal filtered multi-carriers (UFMC) modulations. Statistical analysis of the PAPR is presented by using the complementary cumulative distribution function (CCDF). The MATLAB® simulations have been carried out to implement the CCDF of PAPR and results show that a PAPR gain of 5.4 dB is obtained when the proposed waveform is compared with the standard NOMA-UFMC waveform at clip rate of 10−3, using 4-QAM.

scholarly journals PAPR Reduction of a Universal Filtered Multicarrier Using a Selective Mapping Scheme

2019 ◽  
Vol 54 (5) ◽  
Author(s):  
Farooq Sijal Shawqi ◽  
Ahmed Talaat Hammoodia ◽  
Lukman Audah ◽  
Ammar Ahmed Falih
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Communication Systems ◽  
Average Power ◽  
Mapping Method ◽  
Signal Representation ◽  
Multiple Signal ◽  
Representation Technique ◽  
Selective Mapping ◽  
Papr Performance

The new generation of wireless communication systems involves several different technologies. The universal filtered multicarrier (UFMC) is one of these technologies. UFMC supports various numerology designs; however, the high peak to average power ratio (PAPR) is a major limitation faced by designers. Therefore, diverse approaches have been introduced, such as amplitude clipping, tone reservation, and active constellation extension, to mitigate the PAPR problem. These algorithms produce significant degradation in terms of bit error rate or power consumption. Another proposed solution is multiple signal representation schemes, which have promised to conserve bit error rate performance without power waste. Selected mapping is a multiple signal representation technique that reduces the PAPR without bit error degradation. This paper focuses on integrating the selected mapping method with the UFMC. Simulation results show that the integrated algorithm presents better PAPR performance: the PAPR was reduced by 2.1 dB and 1 dB for UFMC and CP-OFDM, respectively, without bit error rate degradation.

scholarly journals PAPR Reduction Using Fireworks Search Optimization Algorithm in MIMO-OFDM Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lahcen Amhaimar ◽  
Saida Ahyoud ◽  
Ali Elyaakoubi ◽  
Abdelmoumen Kaabal ◽  
Kamal Attari ◽  
...  
Keyword(s):  
Computational Complexity ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multiple Input Multiple Output ◽  
Average Power ◽  
Papr Reduction ◽  
Main Concern ◽  
Ofdm Systems ◽  
Fireworks Algorithm ◽  
Mimo Ofdm

The transceiver combination technology, of orthogonal frequency division multiplexing (OFDM) with multiple-input multiple-output (MIMO), provides a viable alternative to enhance the quality of service and simultaneously to achieve high spectral efficiency and data rate for wireless mobile communication systems. However, the high peak-to-average power ratio (PAPR) is the main concern that should be taken into consideration in the MIMO-OFDM system. Partial transmit sequences (PTSs) is a promising scheme and straightforward method, able to achieve an effective PAPR reduction performance, but it requires an exhaustive search to find the optimum phase factors, which causes high computational complexity increased with the number of subblocks. In this paper, a reduced computational complexity PTS scheme is proposed, based on a novel swarm intelligence algorithm, called fireworks algorithm (FWA). Simulation results confirmed the adequacy and the effectiveness of the proposed method which can effectively reduce the computation complexity while keeping good PAPR reduction. Moreover, it turns out from the results that the proposed PTS scheme-based FWA clearly outperforms the hottest and most important evolutionary algorithm in the literature like simulated annealing (SA), particle swarm optimization (PSO), and genetic algorithm (GA).

scholarly journals Pilot-Aided Frame Synchronization in Optical OFDM Systems

2020 ◽  
Vol 10 (11) ◽  
pp. 4034 ◽  
Author(s):  
Funmilayo B. Offiong ◽  
Sinan Sinanović ◽  
Wasiu O. Popoola
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Visible Light Communication ◽  
Low Complexity ◽  
Frame Synchronization ◽  
Ofdm Systems ◽  
Pilot Symbol ◽  
Pilot Signal ◽  
Symmetric Property

Efficient frame synchronization is essential for data recovery in communication systems. In this study, a single pilot sequence is used to achieve both frame synchronization and peak-to-average power ratio (PAPR) reduction. The two systems considered are direct-current biased optical orthogonal frequency division multiplexing (DCO-OFDM) and asymmetrically clipped O-OFDM (ACO-OFDM). The pilot symbol is allocated to odd indexed subcarriers only. Thus, the synchronization algorithm leverages the mirror symmetric property of the pilot symbol within a frame to detect the start of the pilot signal at the receiver. This scheme has low complexity and gives precise frame synchronization at signal-to-noise ratios as low as 4 dB in an indoor visible light communication (VLC) channel.

scholarly journals Universal Filtered Multi-Carrier System Based on Selective Mapping

2019 ◽  
Vol 37 (6) ◽  
pp. 1257-1263
Author(s):  
Shanlin Wei ◽  
Hui Li ◽  
Wei Cheng ◽  
Wenjie Zhang ◽  
Gang Han ◽  
...  
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Wireless Transmission ◽  
Universal Filter ◽  
M2m Communication ◽  
Fifth Generation ◽  
5G Communication ◽  
Selective Mapping ◽  
Papr Performance ◽  
The Relationship

Internet of things (IoT) and machine-to-machine (M2M) communication are characterized by short periods and bursts. Traditional orthogonal frequency division multiplexing (OFDM) has not meet the demand for such traffic, while IoT and M2M communication will play an important role in the next fifth generation (5G) communication, so it is particularly urgent to study the small packet and low-latency wireless transmission technologies that satisfy IoT and M2M communication. Universal filter multi-carrier (UFMC) is a new kind of filtered wireless transmission mechanism that meets this requirement, but it faces a higher peak-to-average power ratio (PAPR) than OFDM, which affects the energy efficiency of UFMC. Based on the PAPR performance evaluation of several multi-carrier transmission technologies, a universal filtered multi-carrier based on selective mapping (SLM-UFMC) system is proposed, and the relationship between the number of candidate sub-bands and the performance or between the number of carriers and the performance is carried out. The simulation results show that SLM-UFMC can effectively reduce the PAPR of UFMC system, and the PAPR performance is improved by 1.8 dB comparing with the traditional UFMC. It also further indicates that SLM-UFMC is more suitable for IoT and M2M communication in 5G communication.

scholarly journals Hybrid Domain Evaluation PTS with Adaptive Selection Methods for PAPR Reduction

2021 ◽  
Author(s):  
Feng Hu ◽  
Yuan Lu ◽  
Libiao JIN ◽  
Jianbo Liu ◽  
Zhiping Xia ◽  
...  
Keyword(s):  
Computational Complexity ◽  
Frequency Domain ◽  
Average Power ◽  
Optimal Solution ◽  
Low Complexity ◽  
Relative Dispersion ◽  
Practical Applications ◽  
Hybrid Domain ◽  
Multicarrier System ◽  
Papr Performance

Abstract Partial transmit sequence (PTS) technique is a fairly suitable scheme to mitigate the high peak-to-average power ratio (PAPR) problem inherent in 5G multicarrier system-especially considering high-order QAM modulation design. However, the high computational complexity level and the speed of the convergence for optimizing the phases of the transmitting signal restricts this technique in practical applications. In this paper, a low-complexity frequency domain evaluated PTS (F-PTS) based on spacing multi-objective (SMO) processing algorithm is proposed to reduce the PAPR values. The PAPR performance are accurately predicted in terms of modifying relative dispersion in the frequency domain. As a result, the complexity of searching the optimal phase factors and IFFT computing is simplified. Moreover, frequency domain and time domain evaluating PTS (FTD-PTS) is employed to search the optimal solution within reasonable complexity. Simulation results verify that the F-PTS scheme can obtain well secondary peaks with lower computational complexity, and the FTD-PTS scheme effectively reduces PAPR with a faster convergence speed.

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